A rotary piston pump is equipped with at least one motor, which drives at least two counter-rotating rotary pistons. The rotary pistons move in a pump housing. The at least two rotary pistons are disposed on a first output shaft and a second output shaft. The two output shafts are synchronised and driven in such a way that the at least two rotary pistons are in an active interrelation with one another and form an action pair.
German patent application DE 38 25 372 A1 describes a driving engine with two ring cylinders disposed in a plane, in which rotary pistons are disposed. The rotary pistons are fixed on the periphery of a rotor disc sitting in each case in a rotationally fixed manner on a shaft. The rotor discs comprise at the periphery a corresponding slot into which the respective ring cylinders penetrate, wherein the two rotary pistons engage into one another. The task of the driving engine is to cause the rotary pistons to rotate by combustion of a suitable substance and via the latter to drive the shafts. Depending on the design of the gearing, the rotary pistons can rotate both in the same and in the opposite direction.
Disclosed in German patent specification DE 10 2005 062 892 B2 is a rotary piston engine, which is used as an internal combustion engine or as a driven machine. The two rotary pistons disposed diametrically opposite periodically give rise to volume-variable working chambers in a ring cylinder housing. The rotary pistons are connected to one another in a rotationally rigid manner by means of shafts inserted into one another, so that the shafts act on a common output shaft individually via, in each case, a flexible drive system with elliptical transmission discs. The flexible drive can be constituted with a toothed belt, a toothed chain or a chain. By means of two elliptical control toothed pinions in the system, said control toothed pinions being disposed symmetrically, constant pre-tensioning forces are achieved in the strand and at the same time a mutual transfer of the torque with a change in the direction of rotation.
Both the publications cited above deal with driving engines, which are constituted such that an output shaft is moved by means of rotary pistons and a corresponding device. Despite the use of similar components, the machines are not comparable with the rotary piston pumps of the present invention.